FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10, rule 13)
1. Title of the invention: SLITTING UNIT
2. Applicant(s)
NAME NATIONALITY ADDRESS
CEAT LIMITED Indian RPG HOUSE, 463, Dr. Annie Besant
Road, Worli, Mumbai, Maharashtra 400 030, India
3. Preamble to the description
COMPLETE SPECIFICATION
The following specification particularly describes the invention and the manner in which it
is to be performed.

TECHNICAL FIELD
[0001] The present subject matter relates, in general, to a slitting unit and,
particularly but not exclusively, to a slitting unit to be used for slitting of a coated fabric material.
BACKGROUND
[0002] Roll slitting, also known as log slitting or rewind slitting, is a shearing
operation that cuts a large roll of material into strips of narrower rolls. The log slitting terminology goes back to the olden days of sawmills that would cut logs into smaller sections.
[0003] By today's definition, slitting is a process in which a roll or coil of material
may be cut down into a number of smaller strips of narrower measure. The machine used for roll slitting is called a slitter rewinder, a slitter or a slitting unit. These names may be used interchangeably for the same machines. Fabric material slitting units are old and well known and, as commonly re provided with rotating slitting member(s) adapted to slit the fabric material between straight rows, such as between straight adjacent threads. The slitting units have been used primarily as a means for slitting sheet material and particularly coated fabric sheet.
[0004] Slitting may be considered as a practical alternative to other methods due
to its high productivity and the versatility of materials it can manage. Rewind slitting involves rewinding the material through a number of slitting members to form narrower rolls of materials.
BRIEF DESCRIPTION OF DRAWINGS
[0005] The detailed description is described with reference to the accompanying
figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to reference like features and components.
[0006] Fig. 1 illustrates a slitting unit, in accordance with an embodiment of the
present subject matter.

[0007] Fig. 2 illustrates an enlarged side view of a holding member of the slitting
unit, in accordance with another embodiment of the present subject matter.
DETAILED DESCRIPTION
[0008] The present subject matter relates to a slitting unit and particularly to
automation of operation thereof.
[0009] Among the most common of intermediate products utilized in the
manufacturing of tires, are rolls of rubberized coated fabric material or tape. Where it is unnecessary to have the strips of material cut into strips, it is less expensive and more convenient to cut the material on a slitting unit. Conventionally, such a slitting unit is essentially operated with help of a foot or hand-operated switch.
[0010] When the slitting unit starts to operate, a sheet(s) of the material is passed
through slitting assembly of the slitting unit, wherein the material is slit by the slitting assembly into strips of desired width which may then be used as flipper strips to bead cores in the manufacturing of pneumatic tire casings.
[0011] Material for slitting generally comes wounded onto a roll. From this
wounded roll, the material sheets are transferred to the slitting unit to perform slitting operation by the slitting unit. Once consumed, empty roll is removed in order to replace the empty roll with another fully loaded roll wounded with material sheet. To perform this replacement activity, an operator of the slitting unit stops the operation of slitting unit and changes the roll and starts the slitting unit again.
[0012] As discussed earlier, the slitting unit comprises slitting assembly to slit the
material into strips. This slitting assembly further comprises slitting member(s) which
in effect perform the slitting operation for the slitting unit. While starting the slitting
unit to perform the slitting operation, an adjustment of the material sheet below the
slitting member may be required by the operator, to align the material sheet properly
with respect to face of the slitting member to achieve slitting of desired measurement.
[0013] In a conventional arrangement, for moving the slitting assembly of the
slitting unit in an upward and a downward direction, the operator of the slitting unit

may be required to manually rotate a lever in an upward and a downward direction, wherein the lever may be movably connected to the slitting unit.
[0014] To accurately place the material sheet below the slitting assembly, the
operator manually lifts the slitting assembly by rotating the lever by a half revolution. The slitting assembly in upwardly lifted position may be considered in an unengaged posture and in this unengaged posture, the material sheet to be slit is kept beneath the slitting assembly in the desired alignment for slitting.
[0015] In a conventional arrangement, the slitting assembly of slitting unit comes
connected with rotatable lever by a chain-like arrangement. Once the material sheet is
kept in the desired alignment and desired location on the slitting unit, the slitting
assembly then may be brought down to engage with the material sheet to perform
slitting operation. To bring down the slitting assembly to the original position to
engage with the material sheet, the operator may be required to rotate the lever by a
half revolution in an opposite direction of the previous rotation. Since, the chain-like
arrangement is generally formed of a plurality of links having a substantially constant
pitch and a plurality of serially arranged contact surfaces engaging contact surfaces of
the driving and driven means, pitch gap of the chain-like arrangement causes variation
in the slitting of the material, which may lead to non-uniform slitting of the material.
[0016] The slitting assembly may be considered as a group of two separate
elements, the elements being a holding member(s) and slitting member(s). To absorb and counteract any shock or vibration during slitting operation, leaf spring is provided with the slitting assembly in the conventional slitting unit.
[0017] However, due to leaf spring pressure, the operator may be forced to apply
more pressure to press the slitting assembly down, for engaging the slitting assembly with the material sheet for slitting operation, making the process very labor-intensive. This also causes improper pressure on the slitting assembly which in turn may affect the life of slitting assembly members.

[0018] Also, in use, the slitting member(s) wear. In conventional slitting units, if
one slitting member is found to be formed such wear, then this would cause the
operator to change all the slitting members, even if they are in useable condition. This
increases cost of the slitting operation and decreases the life of the slitting members.
[0019] Additionally, as discussed earlier the whole engaging and disengaging
operation of the slitting assembly is based on manual human intervention, skill, and
energy, due to which, the slitting quality may differ from one operator to the other.
Also, the manual handling of the lever may be very difficult for the operator.
[0020] To this end, the slitting unit and implementations of said machine are
described herein. In an embodiment, the slitting unit may be modified to overcome the above-described problems associated with the conventional slitting unit, handling of slitting assembly provided with the slitting unit, along with automation of the slitting operation.
[0021] In accordance with an embodiment of the present subject matter, a slitting
unit with a system to automatize a process of locking and unlocking of slitting assembly in a slitting unit is disclosed.
[0022] In an embodiment, the present invention comprises a slitting unit table and
a slitting unit. The slitting unit is suitably mounted upon the slitting unit table in order to space the slitting unit conveniently above the floor level. The slitting unit has a left-hand side frame and a right-hand side frame. The slitting unit is provided with a transversely arranged driven shaft which is suitably driven by an electric motor through suitable gear reduction and sprocket and chain connection in order to impart traveling or translatory movement to an endless strip or ribbon of material which is advanced to a plurality of slitting assemblies for slitting the material into relatively narrow strips of predetermined width.
[0023] In an example embodiment of the present subject matter, the slitting unit
that is to be used in building of pneumatic tires for vehicles, comprises a base roller to support a material to be slit and a holding shaft which is positioned movably, above

the base roller, wherein the holding shaft reciprocates between a first position and a second position. In an operation, movement of the holding shaft between the first position and the second position is being facilitated by a driven shaft. The driven shaft also reciprocates between the first position and the second position with the help of an electric motor which is controlled via an automated controller provided with the slitting unit.
[0024] Further, the holding shaft may be detachably coupled to the driven shaft
via extended portions provided at both ends of the driven shaft. When the electric motor receives a signal from the controller, the electric motor imparts a reaction force to the driven shaft. Since the holding shaft is movably coupled to the driven shaft, a cam arrangement linking the driven shaft and the holding shaft pushes the holding shaft against motion of the driven shaft, which in turn moves the holding shaft between the first position and the second position.
[0025] The holding shaft comprises a plurality of slitting assemblies to slit the
material, wherein each of the slitting assemblies comprises a holding member mounted on the holding shaft. The holding member of each of the slitting assemblies is being fixedly coupled to said holding shaft by a spacer and a stopper in order to prevent axial movement of the holding members along axis of the holding shaft. Each of the slitting assemblies also comprises a slitting member which is coupled to the holding member, the slitting member being disposed towards the base roller, wherein the slitting member is removably coupled to the holding member.
[0026] Each of the holding members of the slitting unit further comprises a
compression spring which may be connected inside groove at the bottom surface of each of the holding member, wherein the compression spring is to transmit a limited downward moving force causing engagement of the plurality of slitting members with the material to be slit.
[0027] The present subject matter discloses the automated controller, to automate
the process of locking and unlocking slitting assemblies in a slitting unit, through an

electric motor. Detachable slitting members enable ease of replacement of individual slitting members without a need to remove holding shaft. The present invention also allows accommodating slitting members with a difference in degrees of wear which increases usability and life of the slitting members.
[0028] Thus, the present invention reduces difficulties associated with
conventional slitting units by providing an automatic means of positioning the slitting assemblies for slitting the material, which may be operated without a manual lever to acceptable repeatability. The apparatus is adapted to be fitted to a common existing material slitting unit to convert the machine from manual to automatic slitting. The apparatus has an electronic control means which permits an operator to control the locking and unlocking of slitting assemblies.
[0029] These and other advantages of the present subject matter would be
described in greater detail in conjunction with the following figures. While aspects of automatic means of positioning the slitting assemblies for cutting the material can be implemented in any number of different configurations, the embodiments are described in the context of the following device(s) and method(s).
[0030] Fig. 1 illustrates a schematic diagram of a slitting unit 100, according to an
example implementation of the present subject matter. In an embodiment, the slitting unit 100 may suitably be placed upon a slitting unit table 102 in order to space the slitting unit conveniently above the floor level.
[0031] The slitting unit 100 may be provided with a left-hand side frame 106 and
a right-hand side frame 108. The slitting unit 100 may also be provided with a transversely arranged driven shaft 110, suitably driven by an electric motor 112 through suitable gear reduction and sprocket and chain connection in order to impart traveling or translatory movement to strip or ribbon of material which may be advanced to a plurality of slitting assemblies 114-1, 114-2 114-n.., of the slitting unit 100, for slitting the material into relatively narrow strips of predetermined width. It is to be noted that the present invention is described with respect to three number of

slitting assemblies, however, a person skilled in the art will understand that combination of more than three or less than three slitting assemblies is also possible. The use of electric motor 112 advantageously provides uniform cutting for the material without any deviation in depth of slitting of the material.
[0032] In another example embodiment of the present subject matter, the slitting
unit 100 that is to be used in building of pneumatic tires for vehicles, may further comprise a base roller 116 to support a material to be slit and a holding shaft 118 which may be positioned movably, above the base roller 116, wherein the holding shaft 118 may reciprocate between a first position and a second position.
[0033] The base roller 116 may be coupled to a suitable reversible motor which is
operatively connected to the base roller 116 through a suitable gear mechanism, wherein the base roller 116 which extends transversely of the slitting unit 100 beneath the slitting assemblies is to support the live feed of material in the production process to avoid deviation of the material while slitting assemblies slits the material, so that the desired width dimension of the product may be achieved.
[0034] In operation, movement of the holding shaft 118 between the first position
and the second position may be facilitated by the driven shaft 110. The driven shaft 110 reciprocates between the first position and the second position with the help of the electric motor 112 which may be controlled via an automated controller provided with the slitting unit 100.
[0035] Further, the holding shaft 118 may detachably be coupled to the driven
shaft 110 via a cam arrangement or a pulley arrangement, which is well known in the art. After receiving a signal from the controller, the electric motor 112 may impart a reaction force to the driven shaft 110. Since, the holding shaft 118 is detachably coupled to the driven shaft 110, extended portions provided at both of axially extending end portions of the driven shaft 110, pushes the holding shaft 118 against motion of the driven shaft 110, which in turn actuates the holding shaft 118 between the first position and the second position.

[0036] In an operation, the first position may be understood as a position wherein
the plurality of slitting assemblies 114-1, 114-2 114-n.. is not engaged with the material to be slit and thus may be said to be in an unlocked position. The second position may be a position wherein the plurality of slitting assemblies 114-1, 114-2 114-n.. is engaged with the material to be slit for performing the slitting operation on the material. Interchangeably, the second position may also be called as a locked position.
[0037] As may be seen in Fig. 1, the holding shaft 118 comprises a plurality of
slitting assemblies 114-1, 114-2 114-n.. to slit the material, wherein each of the slitting assemblies 114-1, 114-2 114-n.. may comprise a holding member 120 mounted on the holding shaft 118. The holding member 120 of each of the slitting assemblies may be fixedly coupled to said holding shaft 118 by a spacer and a stopper in order to prevent axial movement of the holding members along axis of the holding shaft 118. Each of the slitting assemblies also comprises a slitting member 122 which may be coupled to the holding member 120, the slitting member 122 being disposed towards the base roller 116, wherein the slitting member 122 may be removably coupled to the holding member 120.
[0038] Each of the holding member of the slitting unit 100 may further comprise
a compression spring (not illustrated) which may be connected inside groove at the bottom surface of each of the holding member 120, wherein the compression spring is to transmit a limited downward moving force causing engagement of the plurality of slitting members 114-1, 114-2 114-n.. with the material to be slit. The compression spring applies constant pressure on the slitting member 122 to ensure uniform smooth slitting operation and also acts as a shock absorber for the slitting member 122 during the slitting operation.
[0039] The compression spring at one end may be rigidly secured to the slitting
member 122, and the other end may be rigidly secured to the bottom surface of the holding member 120. It should be apparent that compression spring resiliently

supports the slitting member 122 which may be formed integral with or engaged by holding member 122, for slitting of the material. When subjected to a vertical or axial vibration, the compression spring may be alternately axially compressed and stretched until the energy of the vibration is thereby absorbed. In the event a wider or narrower material is employed, then the compression spring may be readily adjusted to compensate for the difference in the width of the material.
[0040] In an example embodiment, the electric motor 112 may be positioned on a
platform 124, wherein the platform 124 is fixedly attached to the left-hand side frame
106 of the slitting unit 100. The electric motor 112 may be connected to A/C mains
power supply by wire via controller which controls the operation of the electric motor,
wherein the controller may act like any electrical control means such as a switch.
[0041] In another example embodiment, the slitting unit 100 may also be provided
with a material centering unit to adjust the position and alignment of the material on the slitting unit 100 before slitting operation is taken up by the cutting assemblies. The material centering unit may comprise movable centering plate(s) 126-1, 126-2, wherein the centering plate(s) 126-1, 126-2 are movable along the horizontal axis with respect to the left-hand side frame 106 and the right-hand side frame 108. The centering unit may further comprise centering guide(s) 128-1, 128-2, wherein a first centering guide 128-1 is fixedly attached to a first centering plate 126-1 and a second centering guide 128-2 is fixedly attached to a second centering plate 126-2. The first centering guide 128-1 and the second centering guide 128-2 may be provided with circular grooves defined on both ends of the first centering guide 128-1 and the second centering guide 128-2.
[0042] The material centering unit also comprises a first centering plate guide rod
130-1 and a second centering plate guide rod 130-2 arranged parallelly to each other and orthogonally to centering guide(s) 128-1, 128-2. The first centering guide 128-1 and the second centering guide 128-2 is movably coupled to the first centering plate guide rod 130-1 and the second centering plate guide rod 130-2 via said circular

grooves which are defined on both the ends of the first centering guide 128-1 and the second centering guide 128-2. In an operation, the centering guide(s) 128-1, 128-2, and the centering plate(s) 126-1, 126-2, may slide together over the stationary centering plate guide rod(s) 130-1, 130-2 between the left-hand side frame 106 and the right-hand side frame 108 along the horizontal axis.
[0043] In operation of the slitting unit 100, before starting of the slitting operation,
when the material sleeve is inserted and fixed correspondingly at a receiving end of the slitting unit 100, the centering unit properly aligns the material to propel the material into slitting assemblies without substantial stretching tension.
[0044] When the electric motor 112 receives the signal from the controller, then
the electric motor 112 imparts a reaction force to the driven shaft 110. Since, the holding shaft 118 is detachably coupled to the driven shaft 110, extended portions provided at both of axially extending end portions of the driven shaft 110 alongside the left-hand side frame 106 and the right-hand side frame 108 of slitting unit 100, pushes the holding shaft 118 against the motion of the driven shaft 110, which in turn moves the holding shaft 118 between the first position and the second position. With the movement of the holding shaft 118, the plurality of slitting assemblies 114-1, 114-2 114-n.. also operates which in turn may be engaged with the material to be slit via slitting members of each of the slitting assemblies.
[0045] The slitting member 122 of each of the slitting assemblies is rotated in a
direction of arrow 132 in Fig. 1, so that their lower peripheries may be traveling in the same general direction as the feed of the material and at a much higher rate than it travels, and their slight propulsive force may be exerted on the material in a direction coinciding with the feed of the material rather than counter thereto. This slitting of the material by a buzz-saw action in the general direction of the material feed and without substantial longitudinal tension practically eliminates any stretching and narrowing of the bias material and enables slitting of such material at relatively rapid rate and deliver

the slit material in proper condition for further treatment and for ultimate incorporation in manufactured articles such as pneumatic tires.
[0046] In an example embodiment, the present invention also comprises a
separating unit to spread strips of slit material into a single layer web. The separating unit 104 comprises a separator frame 134 located just opposite to the slitting unit table 102 in a direction of movement of the material strips after being passed through slitting assemblies. Further, the separator frame 134 may comprise two support legs to support the separator frame 134 above the ground level, two of the support legs are made retractable. In another example embodiment, the support legs may be telescopic tubes a square, the square upper end of the sleeve into the lower end of the square tube so that the height of the entire separating unit 104 may be adjusted at any time according to the height of the slitting unit 100.
[0047] The separating unit 104 further comprises a separator guide rod 136,
wherein the separator guide rod 136 may be coupled fixedly to the separator frame 134 via a guide rod mounting 138. The separating unit 104 may also comprise a plurality of adjustable separator slides 140-1, 140-2, 140-3, 140-n.
[0048] A rotatable separator roller 142 is fixedly coupled on each of the separator
slides 140-1, 140-2, 140-3, 140-n. In an operation, the material sleeve, supplied to the slitting unit 100, is slit with the slitting member 122 to form strips of slit material extending in a longitudinal direction. Strips of slit material are subsequently pass through the separator roller 142. The strips of slit material may be separated by the separator roller 142 and distributed transversely to a let-off table (not illustrated) direction. The spaced-apart strips of the slit material are then wounded onto spaced apart rollers attached on the surface of the let-off table. The rollers may have a width equal to the width of the strips of the slit material.
[0049] Thus, the separating unit 104 separates and preclude the nesting of the
strips of slit material coming from the slitting unit 100 with each other and reasonably control their positioning on the spaced-apart rollers. Therefore, the working efficiency

of automated slitting unit 100 may greatly be improved, and the labor cost may also be reduced.
[0050] Fig. 2 illustrates a side view in part section, of a holding member 200
constructed in accordance with a modification of the invention. Said holding member is similar to the holding member 120 discussed with respect to fig. 1. The holding member 200 may be latched or locked over the holding shaft 118 by a bolt or a pin (not illustrated) which is urged outwardly by a compression spring confined within a hole 202 in the holding member 200. The diameter of the hole 202 may slightly be more than the diameter of the holding shaft 118 to enable easy retrofitting of the holding member 200 over the holding shaft 118.
[0051] The holding member 200 holds slitting member 122, wherein the slitting
member 122 may turnably be mounted in a respective holding member 200 through a groove 204 by means of adjustable clamping screw (not illustrated) which may extend turnably into a tapped recess 206 of the respective holding member 200. The adjustable clamping screw may be provided with a respective lock nut for holding the respective screw-in adjusted position. In an example embodiment of the present subject matter, the slitting member 122 may easily be removed from the holding member 200 of the slitting assembly, without taking out whole holding shaft 118 or holding member 200 out of the slitting unit 100 and without affecting the operation of several other adjacent slitting assemblies, as shown schematically in fig 1.
[0052] As described above, the slitting unit of the present invention provides a
unique and reliable slitting system that avoids many of the disadvantages of the prior art. For example, with the help of compression spring, the slitting members with premature wear may also be used for the slitting operation. During the slitting operation, variation in input load may cause non-uniform wear of the slitting members and this may lead to a variation in diameters of the slitting members. Conventionally, non-uniform wear of the slitting member may render the slitting member inefficient for slitting operation. However, this is not a case in the present invention, as the present

invention allows for the use of a cutting member with different diameter than the other slitting members.
[0053] For example, in slitting operation due to non-uniform slitting, if one slitting
member gets deteriorated by 2 millimeters and another slitting member gets deteriorated by 1 millimeter then the compression spring of any of the slitting member may be slightly tightened to equalize the pressure exerted by both the slitting members on the material during slitting operation. So, even though, the diameter of slitting members may vary for each of the slitting assemblies, however, depth of slitting of material remains the same throughout, and there is no correlation of slitting depth of material and different diameters of slitting members. Alternatively, in the present invention, any of the slitting members may easily be replaced with taking out holding shaft 118 altogether. Thus, the slitting member according to the present invention is more reliable and less susceptible to permanent wear and failure.
[0054] Thus, the present invention is directed to an improved slitting unit which
also provides for rigid precision support for the slitting members via automatic locking and unlocking of the slitting assemblies in addition to convenient and easy removal and replacement of the slitting members with either a new or a re-sharpened slitting member. The slitting assemblies of the present invention also minimize wear on the moving material and provide for precision support and guidance of the slitting member to assure close slitting tolerances.
[0055] Although implementations for automatization of locking and unlocking of
slitting assemblies in the slitting unit is described, it is to be understood that the present subject matter is not necessarily limited to the specific features of the systems described herein. Rather, the specific features are disclosed as implementations of slitting process automatization in a slitting unit.

I/We Claim:
1. A slitting unit (100) to be used in building of pneumatic tires for vehicles, the
slitting unit (100) comprising:
a base roller (116) to support a material to be slit; and
a holding shaft (118) movably positioned above the base roller (116) reciprocating between a first position and a second position, wherein a movement of the holding shaft (118) is imparted by a driven shaft (110) detachably coupled to the holding shaft (118), via an automated controller provided with the driven shaft (110), the holding shaft (118) comprising:
a plurality of slitting assemblies (114-1, 114-2, 114-n) to slit the material, wherein each of the slitting assemblies comprise:
a holding member (120) mounted on the holding shaft (118);
a slitting member (122) coupled to the holding member (120), the slitting member (122) disposed towards the base roller (116), wherein
the slitting member (122) is removably coupled to the holding member (120).
2. The slitting unit (100) as claimed in claim 1, wherein each of the holding member comprises a compression spring, wherein the compression spring is to transmit a limited downward moving force causing engagement of the slitting member (122) with the material to be slit.
3. The slitting unit (100) as claimed in claim 1, wherein the automated controller is controlled by an electric motor (112) geared to the driven shaft (110).

4. The slitting unit (100) as claimed in claim 1, wherein the slitting member (122) has a variable diameter.
5. The slitting unit (100) as claimed in claim 1, wherein the holding member (120) is mounted on a single holding shaft (118).
U@ 6. The slitting unit (100) as claimed in claim 1, wherein the plurality of slitting assemblies (114-1, 114-2, 114-n) is fixed equidistantly with each other on said holding shaft (118) along a predetermined axial line.
7. The slitting unit (100) as claimed in claim 1, further comprises a centering unit to center align the material on the slitting unit (100).
8. The slitting unit (100) as claimed in claim 1, further comprises a separating unit (104) to spread strips of slit material into a single layer web.